STAT3 and acute myeloid leukemia: In AML cell lines, Apatinib alone and in combination with HHT were studied. As a result of suppressing VEGFR2 expression and downstream signaling cascades, such as PI3K, MAPK, and STAT3, Apatinib and HHT inhibited cell proliferation, reduced the capacity for colony formation, and induced apoptosis and cell cycle arrest in AML cells [324].